Detailed forensic examinations have since determined that the victim suffered a severe blow to the head.

The suspect was arrested yesterday and has been released on police bail pending further enquiries.

Det Insp Ian Iliffe, of West Midlands Police, said: “As part of our investigation we have seized a car from the Small Heath area which is now undergoing detailed forensic tests.

"We have also interviewed a local woman as a witness, who has been helpful in assisting us with our enquiries and the information she has provided will be examined in more detail.

“I would urge anyone who has any information at all, no matter how insignificant it may seem, to contact me as soon as possible.”

Meanwhile detectives continue to appeal for anyone who was in the Forest Road area on the evening of January 28 to come forward. CCTV footage showing two cars and a man running along the road has also been re-released in a bid to trace the occupants.

Det Insp Iliffe and the Major Investigation Review Team can be contacted on the 101 non-emergency number or alternatively information can be given to Crimestoppers anonymously on 0800 555 111.